Au-based catalysts have been reported to be active in the cyclohexane oxidation to K-A oil, but they showed some limitiations in terms of productivity, selectivity and required reaction conditions. The possibility to ...Au-based catalysts have been reported to be active in the cyclohexane oxidation to K-A oil, but they showed some limitiations in terms of productivity, selectivity and required reaction conditions. The possibility to overcome some of these limits has been explored coupling Au with Cu, which can be suitable for undergoing the electron-switch in the initial step of the cyclohexane oxidation. Hence, a bimetallic 2 wt% Au Cu/Al_(2)O_(3) catalyst was tested in the oxidation of cyclohexane, working at mild conditions of 120 ℃ and 4 bar of O_(2). The combination of the catalyst with a very small amount of benzaldehyde used as cheaper and non-toxic radical initiator allowed to obtain a very high productivity of cyclohexanol and cyclohexanone(45 mmol*m L/mgmet*h) with a selectivity of 94%. Moreover, comparing the catalysed reaction with the non-catalysed one, the role of the catalyst has been disclosed.展开更多
Au-Ir and Au-Ru on TiOz catalysts prepared by sequential deposition-precipitation technique were compared with the corresponding monometallics in the hydrogenation of levulinic acid to y-valero]actone. Interestingly t...Au-Ir and Au-Ru on TiOz catalysts prepared by sequential deposition-precipitation technique were compared with the corresponding monometallics in the hydrogenation of levulinic acid to y-valero]actone. Interestingly the addition of Ao to Ir/TiO2 showed a detrimental effect on the activity of Ir monometallic catalyst whereas a positive synergistic effect was shown in the case of Ru. Both catalysts were reduced under H2 to increase the M0-Au0 interaction, From previous DFT calculations and catalytic test, we addressed the lower activity of Au-lr/TiO2 than that of Ir/TiO2 to the interference of Au into the redox mechanism of lr atoms.展开更多
基金The Authors gratefully acknowledge the supportof bilateral project CNR-HAS(MTA)SAC.AD002.037.
文摘Au-based catalysts have been reported to be active in the cyclohexane oxidation to K-A oil, but they showed some limitiations in terms of productivity, selectivity and required reaction conditions. The possibility to overcome some of these limits has been explored coupling Au with Cu, which can be suitable for undergoing the electron-switch in the initial step of the cyclohexane oxidation. Hence, a bimetallic 2 wt% Au Cu/Al_(2)O_(3) catalyst was tested in the oxidation of cyclohexane, working at mild conditions of 120 ℃ and 4 bar of O_(2). The combination of the catalyst with a very small amount of benzaldehyde used as cheaper and non-toxic radical initiator allowed to obtain a very high productivity of cyclohexanol and cyclohexanone(45 mmol*m L/mgmet*h) with a selectivity of 94%. Moreover, comparing the catalysed reaction with the non-catalysed one, the role of the catalyst has been disclosed.
基金financial support granted by project UNAM-PAPIIT IN105416
文摘Au-Ir and Au-Ru on TiOz catalysts prepared by sequential deposition-precipitation technique were compared with the corresponding monometallics in the hydrogenation of levulinic acid to y-valero]actone. Interestingly the addition of Ao to Ir/TiO2 showed a detrimental effect on the activity of Ir monometallic catalyst whereas a positive synergistic effect was shown in the case of Ru. Both catalysts were reduced under H2 to increase the M0-Au0 interaction, From previous DFT calculations and catalytic test, we addressed the lower activity of Au-lr/TiO2 than that of Ir/TiO2 to the interference of Au into the redox mechanism of lr atoms.
